Locomotive throttle valve



May 7, 1929. G. F. BLYsToN LOCOMOTIVE THROTTLE VALVE Filed Jan. 26, 1928 4 INVENTOR l if?? a@ Patented May 7, 1929.

GRIFFITH F. BLYS'ION, OF PITTSBURGH, PENNSYLVANIA.

LGCOMOTIVE THROT'ILE VALVE.

Application filed January 26, 1928. Serial No. 249,555.

The objects which I have in view are, inter alia, as iollows. i

The. provision oli a throttle-Valve which will admit steam to the locomotive cylinders iu such a niauner that the locon'iotive will start smoothly and without jerking.

'ihe provision oi a throttleyalve which is properly balanced so as to easily operate either .in opening` or closing.

The provision oi a throttle-valve without valves and valve -seats which require itrequent grinding but which employs inexpensive and easily and quickly replaceable piston rings.

Th provision ot an improved throttlevalve structure which may be easily and cheaply installedl in connection with the present typo ot standard throttle-valve chainiurs.

ilu Vthe accompanying); drawings, wherein l have illustrated the best embodiment of the principles oi iny invention now known to ine, lijr. 1 is a view in vertical section showing; the upper portion oi a locomotive boiler, the steam dome and the throttle valve,

and Fig. 2 is a view on larger scale showing the 'throttle-valve bushing)Y and twin-pistons partially in elevation and partially in section.

lleierring to the drawings, 1 represents w locmimtivo boiler; 2 the steam dome; 3 the live steam pipe which leads to the locomotive cylinders, and 4l the throttle-valve Al amber which is connected to the steam pe 3 and is shown as of the ordinary f now in general use in railway prace. lnrstead ot the usual valves and valve seats now in general use l seat in the chamber 4 flo a vri cally disposed and cylindrical bushiunj whose upper end protrudes slightly aoove the top oi the chamber 4; and fits snugly in the upper end thereofwhile the lewe: oud oi' the bushing' rests on the floor o l? the chamber and about the circular shoulder G thereon,

tilteam admitted to the lower end of the bushing' 5 througgh the bore 7 for the piston rod and also, preferably, through ports 8 the bottom of the chamber t. ihe budiing 5 is provided with ports 9 ofi relatively large capacity arranged in annular series in the wall oit the bushing just below the top oi' the chamber l and with similar ports 10 just above the top of the chamber. These are the full pressure ports fifi and when the two series of ports are in :lull eonnnunication the cylinders are receiv- .ino the full head oi steam.

Near the lower end of the bushing the same is ln'ovided with an annular series of smaller ports 11 which. are the initial steam admission ports which admit steam from the lower end oi the bushing` when uncovered and are employed to lill the cylinders with steam betere the full pressure ports come into operation.

12 the upper piston and 13 the lower piston both work in the bushing 5 and are mounted in lined relation with each other on the piston rod 141. Thus the upper end et the rod 141 is threaded and screwed through a threaded hole in the center of the piston 12 and its end riveted over as at 15. The perimetral edge of the piston is cut away as at 16 to form anannular seat for the twin piston rings 17 which are held in position by the circular plate 18 wliich is slid upon the piston rod 14 into place. The plate 18 is held in position by sleeve 19 which slipped over the piston rod and supported ilrom below by the piston 13 which in turn is slid up on the piston rod 14.-. The piston 13 .is likewise cut away perimetrally to form a seat for the twin piston rings. The piston 13 and its rings are held in place by the plate 20 on the rod 14 and which is in turn held in position by the nut 21 screwed on a threaded portion of the rod 141.

It is evident that by removing the nut 9.1, the plate 20 may be removed to remove and replace the -lower piston rings, and by also removing the pistonl, the sleeve -19 and 'the plate 18. the upper piston rings may be ren-loved and replaced.

The lower end otl the piston rod conneoted by a linlr 14 to one arm of the bellcrank lever 22 which is pivotally mounted at its angle to a bracket 23 carried by the pipe S and whose other arm has pivotally connected thereto the linlr 2liwhich extends to the locomotive cab and is attached to `lhe lever by which the engineer opens and closes the throttle-valve.

When. the throttle-valve is closed, as illustrated in Fig. 1, the lower piston 18 closes the ports 1.1 while the upper piston 19, is interposed between thc ports 9 and the ports 10, thus interrupting communication between the two series of ports.

Then the link 24 is drawn to the right in Fig. 1 to open the throttle, the twin pistons the twin-pistons continue to rise, the upper piston 12 rises above the ports 10 so that the full pressure is admitted through the ports 10 and the ports 9.

Thus the locomotive is not started with a jerk, as would happen were the throttlevalve opened in such al manner as to admit a full head of steam abruptly. The abrupt admission of steam results in jerking the pulls out the draw-heads.

I also Yprefer to provide the bushing 5 with a fourth annular series o' ports 25 of somewhatlarger capacity than the ports 1l and which are past by the lower piston 13 when the'throttle is open wide so as to increase the admission of steam into the chamber 4t through the lower end of the-bushing 5.'

It is evident' that my improved throttlevalve is balanced as there is constant pressure aga-inst each vpiston and these pressures'are exerted against each other. This greatly increases the ease of operation of the throttle-valve,

Under the present practice double seated valves are used in the valve chamber and when the boiler is washed out these valves are' pulled out, and the valves and their sea-ts are reground. In the case of my improved throttle-valve, all that is necessary is to disconnect the piston rod let from the bell-crank lever 22, pull out they twin. pistons through the upper end ofthe bushing 5- and then, if necessary, replace the packing rings. f

My improvement may be readily and inexpensively installed in standard throttlecars whichcompose the train and frequently valve chambers by fitting in the bushing 5 and the twin-pistons.

That I desire to claim is 1. In a locomotive throttle-valve structure, the combination of the valve chamber` a bushing in said chamber having its end portions in communication with the steam supply, the wall of said bushing near one end having full steam supply ports communicating with said chamber and near itsl other end with reduced steam supply ports also communicating` with said chamber, and twin-pistons working in unison in said bushing and so disposed that as the throttlevalve is opened the reduced supply ports are first brought into operation.

2. In a locomotive throttle-'alve structure, the combination ot the. valve chamber, a bushing in said chamber having its end portions in communication with the steam supply, the Vall of said bushing near onev end having lull steam supply ports communicating with said chamber and near its other end with reduced steam supply ports also communicating with said chamber, twin-pistons working in unison in said bushing and so disposed that as the throttlevalve is opencd'the reduced supply ports are first brought into operation` and additional ports in the bushing wall and communicating with said chamber which are brought into operation by the further movement of the twin-pistons.

3. In a locomotive tln'ottle-valve -structure, the combination of the valvel chamber, a bushing in said chamber having its end portions in communication with the steam supply, a series of ports adjacent to each end oi the bushing and connnuuicatinggr with said chamber, one of said series having the greater capacity than the other series, a pair'of pistons working in said bushing and one of the same controlling the supply ot steam to each series of ports, and means for operating said pistons in unison. said pistons being relatively disposed to bringl the ports of lesser capacity iirst into operation.

Signed at Pittsburgh, Pa., this 21th day of January, 1928.

GRIFFITH F. BLYSTON. 

